Every "Stoplight alternatives" roundup covers the same slice: the API docs and design side, with lists of Scalar, Redocly, Bump and friends. Fair enough — that's most of what Stoplight is. But Stoplight Platform also quietly ran a feature a lot of teams depend on daily and the listicles never mention: hosted mock servers — the stoplight.io/mocks/<workspace>/<project>/… URL your frontend, your QA env, and half your Postman collections point at. This page is about replacing that slice, for free, in about 60 seconds. (For the docs side, we'll point you at the right tools — we're not one of them.)
Being precise here, because "X is dead" posts age badly:
stoplight.io is still up, new workspace signup still works, the hosted mock infrastructure still answers (with Prism-branded errors), and the status page now lives at stoplight.status.smartbear.com. Paid plans start at $44/month (Basic, annual billing), with "instant mock servers" listed as a paid-tier feature.| You used Stoplight for… | Replace it with |
|---|---|
| API reference docs + guides hosting | Scalar, Redocly, or SmartBear API Hub itself — honest answer: not us, we don't host docs |
| Visual OpenAPI design (Studio) | API Hub, or plain-editor + Spectral linting (still open source, still maintained) |
| Spectral / Prism / Elements (the OSS tools) | Nothing yet — all three are Apache-2.0 and alive on npm (checked Sep 2026). Self-hosting Prism keeps working regardless of the platform's fate. |
The hosted mock servers (stoplight.io/mocks/…) | This page. Same OpenAPI document in, hosted URL out — plus writes that actually persist, which Stoplight's mocks never did. |
Stoplight's hosted mocks are generated from your OpenAPI document. So is a Mockbird project — POST the same document:
curl -X POST 'https://mockbird.mockbird.workers.dev/api/projects/import?name=petshop' \
-H 'content-type: application/json' --data-binary @petstore.jsonReal response from the petstore spec we tested with (a Pet schema with name/tag/age):
{ "id": "8b8dzfws98", "adminKey": "…", "imported": true, "kind": "openapi",
"baseUrl": "https://mockbird.mockbird.workers.dev/m/8b8dzfws98",
"resources": [ { "name": "pets", "seeded": 20, "fields": ["name","tag","age"],
"url": "https://mockbird.mockbird.workers.dev/m/8b8dzfws98/pets" } ],
"warnings": [],
"try": "curl 'https://mockbird.mockbird.workers.dev/m/8b8dzfws98/pets?limit=3'" }Your team's new base URL is live immediately, seeded with realistic typed records:
curl 'https://mockbird.mockbird.workers.dev/m/8b8dzfws98/pets?limit=2'
# → [{"id":1,"name":"Problem River Field Work Hour","tag":"car fact point","age":69}, …]And here's the part Stoplight's mocks structurally can't do — they run Prism, which replays your spec's examples, so every write is theater. Ours persist:
curl -X POST 'https://mockbird.mockbird.workers.dev/m/8b8dzfws98/pets' \
-H 'content-type: application/json' -d '{"name":"Waldo","tag":"dog","age":3}'
# → {"name":"Waldo","tag":"dog","age":3,"id":21}
curl 'https://mockbird.mockbird.workers.dev/m/8b8dzfws98/pets/21'
# → the same record. POST → GET it back. A form, a cart, a settings
# page — anything that writes then reads — now actually works.All outputs above are from a real run against production on Sep 6, 2026 (test project deleted afterwards). No signup needed — anonymous projects are claimable later. Prefer a UI? Open the dashboard import panel and paste the spec.
Stoplight's hosted mocks speak Prism's control surface (Prefer headers / __code-style params). Everything has a query-param equivalent here, which also means it works from a browser URL bar or a no-code tool:
| Stoplight / Prism | Mockbird |
|---|---|
https://stoplight.io/mocks/acme/shop/123/pets | https://mockbird.mockbird.workers.dev/m/<project>/pets |
Prefer: code=404 — force a status | ?mock_status=404 (docs) |
Prefer: dynamic=true — faker-generated data | default behavior — every project is seeded with realistic typed records (no LLM, deterministic reseed with ?seed=N) |
Prefer: example=… — pick a named example | closest equivalent: named snapshots — pin any request to a saved dataset with ?mock_snapshot=name |
| request validation errors from spec | ?mock_validate=1 on writes → real 422s with per-field messages (guide) — narrower than Prism's full contract checking, honesty note below |
| no latency / failure injection | ?mock_delay=2000, ?mock_seq=500,500,200 retry drills, ?mock_chaos=0.3, ?mock_ratelimit=… |
| writes replay examples, nothing stored | full CRUD with persistence, filtering, sorting, pagination, relations, search |
examples replay on non-CRUD paths (login, /search, RPC verbs) | kept: those operations import as custom routes serving your spec's example verbatim (any content type) |
The spec goes both ways. Every project serves a live /openapi.json that tracks whatever your schema evolves into — so you can leave us the same way you arrived, including straight back into self-hosted Prism:
curl -o api.json 'https://mockbird.mockbird.workers.dev/m/8b8dzfws98/openapi.json'
npx @stoplight/prism-cli mock api.json # back on localhost, no platform involved| Stoplight hosted mocks | Prism self-host | SmartBear API Hub | Mockbird | |
|---|---|---|---|---|
| Price | paid platform (Basic from $44/mo annual; future uncertain) | free, Apache-2.0 | enterprise pricing | free while in beta |
| Hosted URL others can hit | yes | no — you host it | yes | yes — 10,000 req/project/day, no signup |
| Stateful writes | no (Prism engine) | no (roadmap, unshipped) | no (same engine family) | yes — persistent CRUD + snapshots |
| Docs & design tooling | excellent — its real product | — | excellent | none — not a docs tool |
| Contract validation | yes | excellent (proxy mode) | yes | write-validation 422s only |
| Failure/latency drills | status picking | status picking | status picking | status, delay, sequences, chaos, jitter, rate-limit |
| Platform longevity risk | the reason this page exists | none — it's your box | SmartBear's flagship, safe bet | young product, honest about it — but eject any time: openapi.json, db.json, Postman, types |
Written by the Mockbird maker — bias disclosed. Where Stoplight genuinely wins even now: the visual OpenAPI designer and hosted docs are excellent and we have no equivalent; Spectral-powered style guides are the industry standard; and Prism's full request/response contract validation is deeper than our write-time 422s. If the docs side matters to you, genuinely consider Scalar, Redocly, or API Hub. Facts above checked live September 6, 2026: stoplight.io reachable, signup open, pricing page ($44/56 Basic, $113/147 Startup, $362/453 Pro Team, annual/monthly), mock infra answering with Prism-branded JSON errors, Prism v5.x current on npm; October 2025 community coverage as linked claims by their authors, not our findings.
Full API reference in the docs. Related guides: Prism alternative (the CLI angle) · mock server from an OpenAPI spec · SwaggerHub mock alternative · mock API with validation errors · free mock API tools compared. Create your API →